A191859 The primes created by concatenation of anti-divisors in A191647.

2, 3, 23, 347, 349, 311, 391627, 3471331, 384067, 2310175897, 239111323273399, 23167, 3784097136227, 235983149249, 3428116271, 37111677121283, 23293, 3471949133311, 231314228398154359, 378112153101159371, 2379127163381

Offset

1,1

Comments

a(n) is the concatenation of the anti-divisors of A191647(n).

Links

Klaus Brockhaus, Table of n, a(n) for n = 1..1000

Example

A191647(6) = 16, the anti-divisors of 16 are 3, 11. Hence a(6) = 311.
A191647(8) = 46, the anti-divisors of 46 are 3, 4, 7, 13, 31. Hence a(8) = 3471331.

Prog

(Magma) Antidivisors:=func< n | [ d: d in [2..n-1] | n mod d ne 0 and ( (IsEven(d) and 2*n mod d eq 0) or (IsOdd(d) and ((2*n-1) mod d eq 0 or (2*n+1) mod d eq 0)) ) ] >; CAD:=function(n); A:=Antidivisors(n); S:=[]; for k in [1..#A] do S:= Intseq(A[k]) cat S; end for; p:=Seqint(S); return p; end function; A191859List:=func< m | [ p: n in [1..m] | IsPrime(p) where p is CAD(n) ] >; A191859List(600);

Crossrefs

Cf. A191647, A066272, A130846, A120712.

Sequence in context: A235934 A064888 A104458 * A289550 A154553 A160341

Adjacent sequences: A191856 A191857 A191858 * A191860 A191861 A191862

Keyword

nonn,base

Author

Klaus Brockhaus, Jun 18 2011

Status

approved